Assigning Tracking Numbers to Campaigns can be done in the Campaign's Window.
From the Main Menu, Click on Affiliates -> Campaigns.
Open the Campaign Window by clicking on the Campaign Name.
Under the Campaign Information you should be able to see if there is a number assigned to this Campaign.
If the Assigned Number Field is Blank (No Number Assigned) there is no Tracking Number assigned to this campaign and the campaign.
To Assign a Tracking Number, Click on the icon 
From the Phone Number drop down, select the Tracking Number you want to assign to the Campaign.
Key Considerations:
- Only available Tracking Numbers that are not assigned to other campaigns will be listed in the dropdown.
- If there are no tracking numbers listed in the dropdown, you either haven't purchased tracking numbers or you don't have any tracking numbers available.